Machine having overhang supports for pallets

ABSTRACT

Carriers are suspended on vertical rails providing a cantilever support for pallets which permit a machining operation to be performed on the bottom face of a workpiece as well as the other surfaces thereof. A further novelty resides in the drive for the carriers by a single strand hollow pin conveyor chain which is bendable in a horizontal plane so that it may assume any configuration depending on the type of machining to be performed and the area which the machine is to occupy. The pallet may be movably supported on the carrier or may be fixed thereto and when movably supported, the pallet is shifted in two directions and secured in fixed position at a station. The chain has wear plates thereon and wear plates are mounted on the carrier in engagement with those on the chain which frictionally drives the carriers until one carrier is stopped as the chain continues to advance.

United States Patent Zilahy et a1.

[45] Mar. 7, 1972 [54] MACHINE HAVING OVERHANG SUPPORTS FOR PALLETS [72]Inventors: Zoltan E. Zilahy, Nutley; Anthony L. Dato, River Vale, bothof NJ.

[73] Assignee: Standard Tool 8: Manufacturing Co.

[22] Filed: Apr. 30, 1970 [211 App]. No.: 33,440

[56] References Cited UNlTED STATES PATENTS Cargill ..29/2o0 A Holmes......198/l9 X Brown 198/ 19 Primary Examiner-Edward A. SrokaAttorney-Harness, Dickey & Pierce [57] ABSTRACT Carriers are suspendedon vertical rails providing a cantilever support for pallets whichpermit a machining operation to be performed on the bottom face of aworkpiece as well as the other surfaces thereof. A further noveltyresides in the drive for the carriers by a single strand hollow pinconveyor chain which is bendable in a horizontal plane so that it mayassume any configuration depending on the type of machining to beperformed and the area which the machine is to occupy. The pallet may bemovably supported on the carrier or may be fixed thereto and whenmovably supported, the pallet is shifted in two directions and securedin fixed position at a station. The chain has wear plates thereon andwear plates are mounted on the carrier in engagement with those on thechain which frictionally drives the carriers until one carrier isstopped as the chain continues to advance.

15 Claims, 8 Drawing Figures MACHINE HAVING OVERHANG SUPPORTS FORPALLETS BACKGROUND OF THE INVENTION Reference may be had to D. A.Cargill, Reissue U.S. Pat. No. Re. 25,886 to show the state of the artof pallets which when stopped permits the drive to continue to advance.

SUMMARY OF THE INVENTION The invention pertains to a support made up ofsections which have vertical rails on which carriers are supported incantilever. The rails are spaced by blocks to provide a passageway atthe top for a single strand conveyor chain made up of links which hingein a horizontal plane. The chain has wear plates thereon which contactswear plates on the carriers to produce a friction drive therebetween.The carrier has a pair of rollers which engage the rear side of thevertical rail at the top and a pair of eccentrically mounted rollerswhich engage the front side of the rail at the bottom which areadjustable to position the supporting extension for the pallet in ahorizontal plane. The rails also support a horizontal brake flange whichis engageable by brake shoes on a vertical shiftable support actuated byone end of a tiltable bar through a spring for applying a predeterminedclamping pressure on both sides of the brake flange. The opposite end ofthe tiltable bar has a roller engageable by a cam end of a lever whichis actuated by a plunger when engaging a stop or a stopped carrier forapplying a predetermined pressure to the brake shoes. This will slowdown the carrier as the wear plates on the chain advance relative to thewear plate on the carriers. When the preceeding carrier again moves, theplunger will be released releasing the brake shoes and permitting thecarrier to again be advanced by the chain. The carriers have a forwardextension for supporting the pallets and have a large central openingwhich is aligned with a large central opening through the pallet whichpermits a machine operation to be performed on the bottom portion of theworkpiece supported thereby. The pallet has slots in the side edgeswhich diverge at the outer ends, two of which receive a pair of pinswhich are smaller in diameter than the width of the slots to providesubstantial clearance which permits the pallet to be shifted in twodirections when being clamped at a station. A wedge plate has a springpressed finger which engages a slot and moves the pallet parallel to theconveyor chain while the wedge plates move the pallet at right anglethereto into clamping engagement with a stationary wedge plate. It iswithin the purview of the invention to secure the pallet in fixedrelation to the carrier extension. When loosely mounted thereon, thepallet may be removed and rotated in increments of 90 and may bereturned to the same or on a different carrier. When removed, amachining operation may be performed on the workpiece at a stationremote from the conveyor chain and rails. The braking arrangement may beeliminated and resilient means may be provided between the carriers toproduce the stopping of the carriers at a station or one relative to theother without producing too great an impact.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing anundulated path for the conveyor chain and supporting rails for advancingthe carriers and pallets to different stations;

FIG. 2 is a broken plan view of a carrier with a pallet thereon beforebeing accurately positioned and clamped at a machining station;

FIG. 3 is a view of the structure illustrated in FIG. 2, as viewed fromline 3-3 thereof;

FIG. 4 is a view of structure, similar to that illustrated in FIG. 2,showing the pallet and carrier mounted on a vertical support andfrictionally driven by a conveyor chain hingeable in a horizontal plane;

FIG. 5 is a view of the structure illustrated in FIG. 4, as viewed fromthe point 5 thereof;

FIG. 6 is a view, partly in action, of the structure illustrated in FIG.5, as viewed from the point-6 thereof;

FIG. 7 is an enlarged sectional view of the structure illustrated inFIG. 6, taken on the line 7-'7 thereof, and

FIG. 8 is the reduced view of the structure illustrated in FIG. 6,showing the standards to which the vertical supports are secured.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I, acontinuous conveyor chain 11, by way of example, is illustrated aspassing along an upper path 12, a lefthand path 13, reversing itself at14 to pass along a path 15, reversing itself at 16 and then advancingangularly along a path 17 and reversing itself at I8. The chain thenmoves along a path 19, an arcuate path 21, a straight path 22, reversingitself at 23, advances along a path 24, reversing itself at 25 to thefirst mentioned path 12. Along these different paths of the chain, anynumber of stations 26 and 27 are positioned in spaced relation to eachother. Only a few of the stations are herein illustrated which may beautomatic or manual to perform different operations on a workpiecemounted on the pallet which is supported on a carrier and advanced bythe conveyor chain. Along the path of the conveyor chain, as illustratedin FIG. 8, standards 28 are provided for supporting vertically disposedrails 29 and 31 which are spaced apart by blocks 32. The rails aresecured to the standard by angle rail member 33 and by screws 34. Theconveyor chain 11 is disposed between the rails 29 and 31 above theblocks 32 having inner links 36 and outer links 37 connected by headedsleeves 38 with the outer link spaced by bearing sleeves 39 engaged bythe inner links 36 and rollers 41, as illustrated in FIG. 7. The linksare disposed in horizontal planes to permit them to move along anundulated horizontal path. Hardened wear plates 42 are secured to pairsof the sleeves 38 by bolts 43. These plates ride upon hardened wearstrips 44 secured to the upper end of the rails 29 and 31. Carriers 45for pallets 46 have wear plate 47 provided thereon which are supportedon the conveyor chain wear plates 42. The carrier has a pair of spacedrollers 48 at the top rear edge which engages the remote face of theangle rail member 33. The bottom of the carrier has a rearwardlyextending flange 49 on which rollers 51 mounted on eccentric stub shafts52 are supported. The rollers are adjustable to locate a palletsupporting extension 53 in a horizontal plane. The downward weight ofthe carrier and the wear plate 47 is supported on the wear plates 42 ofthe conveyor chain 11 which advances the carrier 45, the pallet 46 andworkpiece carried thereby along the rails 29 and 31. The carrier may bestopped at any station or when contacting a carrier directly aheadthereof which is slowed down or stopped. The wear plates 42 on the chainwill continue to advance while engaging the wear plates 47 of thecarrier without any substantial wear occurring therebetween. Thisstoppage could occur by the use of urethane or like bumpers or springsto cushion the shock which would otherwise occur. Preferably the carrieris slowed. downand stopped by a braking action. While various typesofbrakes may be employed, a pinch type of brake is herein illustrated. Abrake flange 54 is supported on the rail. 29 by a supporting web'55which forms aT-shaped section with the brake flange. The bottom of thecarrier 45 is provided with a pair of headed pins 56* on' which a boss57 is slidablysupported. The boss has a slot 58 on its inner portionwhich: straddles the brake flange 54. The portion 59 above the slotssupports a brake pad 61 which is fixed thereto. The bottom portion 62supports a capsule 63 having a brake pad 64 at the top, a plurality ofBelleville spring washers 65 and a disc 66 at the bottom. The disc 66 isengaged by an adjustable stud 67 on the adjacent ends of a rockable bar68 which is secured to the boss' 57 by a-pivot 69. When. the stud ismoved'upwardly, the'brake pad 64 engages the'bottom side of the'brakeflange 54' and'draws the boss 57 downwardly on the headed pins 56to movethe brake shoe 61 with a like force against the upperface of-the brakeflange 54. The two brake shoes clamp the flange with a pressure exertedby the Belleville' spring washers 65 which is adjustable. The forwardend of the rocking bar 68carries a roller7l engaged by a cam surface 72on the end of a lever 73 of substantial length which is pivoted to theboss 57 on a headed stud 74. A spring 75 urges the lever 73 in aclockwise direction, as illustrated in FIG. 5. The upper end of thelever carries an adjustable screw 76 which is aligned with the end of aplunger 77 mounted for longitudinal movement in an aperture 78 in thecarrier.

The bottom of the lever 73 also has an arcuate portion 79 incontinuation of the cam surface 72 to form a dwell section so that thepressure produced by the Belleville spring washers 65 can be set toproduce a predetermined braking force on the brake shoes 61 and 64irrespective of the amount the lever was moved. The end 81 of theplunger 77 is located in position to strike a stop element positionalong a path of the conveyor chain 11 or to strike the face of ahardened block 82 attached to the opposite end of the carrier 45 whenthe stopped preceding carrier is locatedon the straight or curvedportion of the path of the conveyor chain. The striking of the end 81against a stop element or a preceding carrier stops the plunger 77 whichmoves the advancing lever 73 counterclockwise camming the roller 71downwardly to rock the tiltable bar 68 and move the threaded screw 67upwardly to apply a braking force to the brake shoes 61 and 64. Thebraking pressure can be accurately adjusted relative to the length ofthe cam surface 72 after which a dwell will occur when the roller isengaged by an arcuate portion 79 upon further movement of the lever.This will prevent the brake shoes from grabbing and slowly applies aholding pressure to permit the wear plates 42 of the chain to sliderelative to the wear plates 47 on the carrier. In this manner, thecarrier is slowed and eventually stopped without striking a precedingcarrier with any substantial force.

The horizontal extension 53 of the carrier 45 provides a cantileversupport for the pallet 46 which may be fixed thereon by screws securedin threaded apertures 83 provided on the extension. This may be desiredwhen manual operations are to be performed at the machining stations.When automatic operations are to be performed at the stations, a pair ofpins 84 extend upwardly from the extension 53 which project within slots85 provided at the center of each edge of the pallet. The width of theslots 85 is substantially greater than the diameter of the pins so thatthe pallet can be shifted relative thereto. The outer portion of theslots 85 diverge at 86 for engagement by a spring pressed finger 87 on awedge-type locking element 88 movable toward a fixed wedge-type lockingplate 89 provided at the working station. When the carrier is stopped atthe station, the locking element 88 is advanced to first have the finger87 engage the diverging portion 86 of the adjacent slot 85 to shift thepallet parallel to the path of movement of the conveyor chain. Thefurther movement of the locking element 88 causes the wedge portion 91thereof to engage the adjacent edge of the pallet and force it intoengagement with the like wedge portion 92 on the fixed locking plate 89.This cams the pallet upwardly into fixed position while shifting normalto the path of movement of the chain conveyor to have it accuratelylocated in both directions.

As illustrated in FIG. 4, the horizontal extension 53 of the carrier 45has a large aperture 93 which is aligned with an aperture 94 in thecenter of the pallet. This permits machining to be undertaken on thebottom of the workpiece supported by the pallet. Substantially allportions of the workpiece may be machined, the sides, top and bottomthereof without removing it from the pallet. The retention of the palleton the carrier by the pins 84 permits the pallet to be raised androtated by increments of 90 to different positions or to be entirelyremoved so that the workpiece may be machined by a manual operation at aremote point and returned to the same or a different carrier.

The rails 29 and 31 are preferably provided in sections of predeterminedlength secured together on the standards 28. The arcuate sections are ofthe same or different lengths supported by other standards 28 to providea continuous rail of substantially any configuration. The arcuate pathhas such a radius as to permit the carriers to travel therealong whilemaintaining the plunger 77 aligned with the block 82 on a precedingcarrier so that contact may always occur therebetween at any positionalong the conveyor chain path.

Should extra time be required for an operation at a work station, thecarrier may remain stationary for a longer period than the allotted timeas one or more additional carriers will be stopped thereby as they areadvanced by the conveyor chain. When the retained carrier is released,the other carriers are free to advance to the station and as the workprogresses all of the carriers will be advanced by the chain in spacedrelation to each other. The supporting of the carrier on the verticalrails permits the horizontal extension to be supported in cantilever sothat machining can occur on the bottom of the workpiece when aperturesare provided in the carrier and the pallet. The hinging of the chain inthe horizontal path permits the chain to travel in any direction as aclosed loop or in an undulated or straight path as necessity dictates.The machining stations may be placed within or outside of the loop orboth and any of the carriers can be stopped at any time at any placealong the conveyor chain path as the conveyor chain is drivencontinuously at a constant speed. This provides minimum machine timewhile permitting extra time for the machine operation at the stations asmay be required from time to time. The stopping of the carrier for theextra period of time also permits the changing and adjustment of thetools and other minor maintenance requirements without shutting down theconveyor line.

lclaim: i

1. In a work-conveying device, a plurality of carriers for supportingand advancing workpieces, a support having straight and arcuate sectionsupon which said carriers are movable, a chain having the links disposedsubstantially horizontal for advancing said carriers on the support withthe links on the chain pivotable in a horizontal plane, wear plates onthe chain and carriers providing a driving relation therebetween whenthe carriers are free to advance, and stop means on the carriers whichwhen engaged interrupt their advancement and permit the wear plates onthe chain to continue to advance relative to the wear plate on thestopped carriers.

2. In a work-conveying device as recited in claim 1, wherein said stopmeans is a brake, and movable means supported by the carrier foroperating said brake when the movable means is actuated by a stopelement or by the preceeding stopped carrier.

3. In a work-conveying device as recited in claim 2, wherein said brakeembodies a horizontally extending brake flange on the carrier support,and brake shoes on said carriers which are relatively moved upon theactuation of the lever means to have the brake shoes clamp on oppositesides of the brake flange.

4. In a work-conveying device as recited in claim 3, wherein saidmovable means is a lever and wherein an actuatable element is operatedby the lever for relatively moving said brake shoe, and resilient meansprovided between the actuatable element and the movable brake shoe forproducing a braking force by said resilient means.

5. In a work-conveying device as recited in claim 4, wherein the leverhas a cam portion in engagement with the actuatable element for applyingpressure to the movable brake shoe through said resilient means, and adwell portion in extension of said cam portion which limits the force onthe brake shoe applied through said resilient means by the furthermovement of said lever.

6. In a work-conveying device as recited in claim 5, wherein plungermeans is supported by the carrier with one end extending forwardlythereof in alignment with the end of the preceding carrier for actuatingthe lever when the plunger is moved relative to the carrier uponstriking a stop element or the preceeding carrier.

7. In a work-conveying device as recited in claim 1, wherein the carrierhas a laterally projecting pallet supporting extension suspended incantilever from one side thereof.

8. In a work-conveying device as recited in claim 7, wherein a pallet ismovably retained on said supporting extension.

9. In a work-conveying device as recited in claim 8, wherein said pallethas an aperture therethrough alignable with an aperture through thesupporting extension which permits the bottom of the workpiece supportedby the pallet to be operated upon.

10. In a work-conveying device as recited in claim 9, wherein the palletsupports are pins extending upwardly from the forwardly extendingportion of the carrier, the edges of said pallet having a slot thereinsubstantially wider than the diameter: of the pins so as to be movablerelative thereto when retained thereby, said slots having divergingouter edge portions, a wedge plate carried at a station where work is tobe performed, and a movable wedge element having a spring pressed fingerwith converging sides at the end which engage the diverging side edgesof the slot to shift the pallet parallel to the support while the wedgeblock moves the pallet normal thereto and secures the pallet which isaccurately located at the stations.

11. In a work-conveying device, a plurality of carriers for supportingand advancing workpieces, vertically disposed rail means along whichsaid carriers are advanced, a continuous horizontally bendable chain onsaid rail means, means on said chain having frictional engagement withsaid carriers for advancing said carriers therewith when the carriersare free to be advanced, a lateral extension on the carriers on which apallet is supported, and means on said carriers in engagement with aside of said rail means to prevent the carriers from tilting laterallyrelative thereto.

12. In a work-conveying device as recited in claim 11, wherein a palletsupported by said carrier extension has an aperture therethrough alignedwith an aperture through the extension through which an operation may beperformed on a workpiece supported on the pallet.

13. In a work-conveying device as recited in claim 12, wherein saidpallet is movably supported on said carrier extensron.

14. In a work-conveying device as recited in claim 13, wherein saidpallet is movably supported on said extension in one of increments ofangular displacement in the plane of the pallet.

15. In a work-conveying device as recited in claim 14, wherein means areprovided for clamping the pallet at a station along the rail means as itis shifted into accurately located position longitudinally and normallyto said rail means.

1. In a work-conveying device, a plurality of carriers for supportingand advancing workpieces, a support having straight and arcuate sectionsupon which said carriers are movable, a chain having the links disposedsubstantially horizontal for advancing said carriers on the support withthe links on the chain pivotable in A horizontal plane, wear plates onthe chain and carriers providing a driving relation therebetween whenthe carriers are free to advance, and stop means on the carriers whichwhen engaged interrupt their advancement and permit the wear plates onthe chain to continue to advance relative to the wear plate on thestopped carriers.
 2. In a work-conveying device as recited in claim 1,wherein said stop means is a brake, and movable means supported by thecarrier for operating said brake when the movable means is actuated by astop element or by the preceeding stopped carrier.
 3. In awork-conveying device as recited in claim 2, wherein said brake embodiesa horizontally extending brake flange on the carrier support, and brakeshoes on said carriers which are relatively moved upon the actuation ofthe lever means to have the brake shoes clamp on opposite sides of thebrake flange.
 4. In a work-conveying device as recited in claim 3,wherein said movable means is a lever and wherein an actuatable elementis operated by the lever for relatively moving said brake shoe, andresilient means provided between the actuatable element and the movablebrake shoe for producing a braking force by said resilient means.
 5. Ina work-conveying device as recited in claim 4, wherein the lever has acam portion in engagement with the actuatable element for applyingpressure to the movable brake shoe through said resilient means, and adwell portion in extension of said cam portion which limits the force onthe brake shoe applied through said resilient means by the furthermovement of said lever.
 6. In a work-conveying device as recited inclaim 5, wherein plunger means is supported by the carrier with one endextending forwardly thereof in alignment with the end of the precedingcarrier for actuating the lever when the plunger is moved relative tothe carrier upon striking a stop element or the preceeding carrier. 7.In a work-conveying device as recited in claim 1, wherein the carrierhas a laterally projecting pallet supporting extension suspended incantilever from one side thereof.
 8. In a work-conveying device asrecited in claim 7, wherein a pallet is movably retained on saidsupporting extension.
 9. In a work-conveying device as recited in claim8, wherein said pallet has an aperture therethrough alignable with anaperture through the supporting extension which permits the bottom ofthe workpiece supported by the pallet to be operated upon.
 10. In awork-conveying device as recited in claim 9, wherein the pallet supportsare pins extending upwardly from the forwardly extending portion of thecarrier, the edges of said pallet having a slot therein substantiallywider than the diameter of the pins so as to be movable relative theretowhen retained thereby, said slots having diverging outer edge portions,a wedge plate carried at a station where work is to be performed, and amovable wedge element having a spring pressed finger with convergingsides at the end which engage the diverging side edges of the slot toshift the pallet parallel to the support while the wedge block moves thepallet normal thereto and secures the pallet which is accurately locatedat the stations.
 11. In a work-conveying device, a plurality of carriersfor supporting and advancing workpieces, vertically disposed rail meansalong which said carriers are advanced, a continuous horizontallybendable chain on said rail means, means on said chain having frictionalengagement with said carriers for advancing said carriers therewith whenthe carriers are free to be advanced, a lateral extension on thecarriers on which a pallet is supported, and means on said carriers inengagement with a side of said rail means to prevent the carriers fromtilting laterally relative thereto.
 12. In a work-conveying device asrecited in claim 11, wherein a pallet supported by said carrierextension has an aperture therethrough aligned with an aperture throughthe extension through which an operation may be perFormed on a workpiecesupported on the pallet.
 13. In a work-conveying device as recited inclaim 12, wherein said pallet is movably supported on said carrierextension.
 14. In a work-conveying device as recited in claim 13,wherein said pallet is movably supported on said extension in one of 90*increments of angular displacement in the plane of the pallet.
 15. In awork-conveying device as recited in claim 14, wherein means are providedfor clamping the pallet at a station along the rail means as it isshifted into accurately located position longitudinally and normally tosaid rail means.